Nutrition and health in salmon
Salmon need to be supplied through their diet with EPA and DHA, just like humans. Good health requires a robust heart, and nutrition that supports tissue recovery and curbs inflammation can have positive effects on the cardiovascular health of salmon. These effects can be mapped in a swim tunnel, by measuring the maximum heart rate and oxygen uptake.
Genes play an important role in both species, but regardless of your species, there will be positive health effects from both physical activity and proper nutrition.
Nofima has developed a swim tunnel it calls “The Flume”, where fish can swim at increasing speed until they are exhausted. The swim tunnel is a kind of fish treadmill, and is used to conduct endurance tests, monitoring heart rate and oxygen consumption.
It provides a good picture of the health and performance of salmon, just as a treadmill does for humans. Assisted by experiments carried out in “The Flume”, BioMar has explored the impact on cardiovascular health of varying levels of fatty acid content and source of feed.
Exercise and nutrition both affect cardiac growth, contractility and the production of red blood cells. Interval training at medium intensity of smolt has been shown to increase their resistance to infection of IPN (Infectious pancreatic necrosis) and the winter ulcer bacteria Moritella viscosa.
Just as in humans, fish react positively to exercise, and in the same way overtraining can lower the immune system and resistance to disease. If sufficient recovery time is not allowed after exercise and periods of heavy muscular activity, it will detrimentally affect the immune system and cause adverse inflammatory reactions.
Proper nutrition can produce beneficial effects similar to exercise. There is also an interaction between physical activity and nutrition. For example, supplements of EPA and DHA combined with exercise have a positive result on health. This kind of interaction is a new and exciting field of research.
A number of studies have shown that EPA and DHA from Antarctic krill (Euphasia superba) achieve a different distribution in the body than a corresponding amount of the essential omega-3 fatty acids acquired from other sources. Inter alia, it results in increased levels of EPA and DHA in major organs such as the brain and heart. It also leads to a reduced accumulation of fat in the liver, as well as a reduced amount of fat deposited amongst organs of the abdominal cavity.
Research suggests that both exercise and nutrition affect the ability of fish to resist disease, and we see clear signs that proper nutrition with increased access to EPA and DHA makes fish more resistant to viral diseases such as HSMI and CMS.
The BioMar feed Qardio has been developed through a staged process where qualitative effects were detected and documented under controlled trials. The feed has been tested under realistic commercial conditions in the field, and has yielded measurable effects in terms of properties such as:
- Relative heart size
- Virus quantities in central organs under infection experiments (HSMI)
- Level of tissue injury during viral infection (infection experiments: HSMI, field: HSMI + CMS)
- Changed fatty acid composition of the heart muscle
Higher slaughter yield due to altered fat distribution with a lower percentage of abdominal fat